Re-add Out to ExtractComponent (#23334)

beicause · web-flow · commit 5c36ecf80590 · 2026-03-28T02:54:53.000Z
# Objective Fixes #22863. Fixes #22999. Fixes #23142. ## Solution 1. Re-add `Out` type to `ExtractComponent`. Rename `SyncComponent::Out` to `SyncComponent::Target`, which is used to clean up components when removing, so that the output of extraction can be different from `SyncComponent::Target`. 2. Add `#[extract_component_sync_target]` attribute for `#[derive(ExtractComponent)]` to specify `SyncComponent::Target`. ## Testing Tested `ssr` and `order_independent_transparency` examples. There may be other places where derived components need to be cleaned up, but finding them is somewhat challenging.
diff --git a/_release-content/migration-guides/extract_refactor.md b/_release-content/migration-guides/extract_refactor.md
@@ -1,13 +1,17 @@
 ---
 title: "`ExtractComponent` refactor"
-pull_requests: [22766]
+pull_requests: [22766, 23334]
 ---
 
-The `Out` type from `ExtractComponent` has been split into a separate `SyncComponent` trait.
+Previously, `SyncComponentPlugin`/`ExtractComponentPlugin` would despawn the render entity thus removing all the derived components if the component was removed. Now the render entity is no longer despawned and only the `Target` components of `SyncComponent` trait are removed.
 
-Both traits have also gotten an optional marker type that can be used to bypass orphan rules, see the docs for details.
+`SyncComponent` is a subtrait of `ExtractComponent` and you must implement it to clean up extracted and derived components.
 
 ```rust,ignore
+impl SyncComponent for MyComponent {
+    type Target = (Self, OtherDerivedComponents);
+}
+
 impl ExtractComponent for MyComponent {
     type QueryData = ();
     type QueryFilter = ();
@@ -21,21 +25,12 @@ impl ExtractComponent for MyComponent {
 }
 ```
 
-After:
+You can also specify the sync target (default to `Self`) using `extract_component_sync_target` attribute in derive macros.
 
 ```rust,ignore
-impl SyncComponent for MyComponent {
-    type Out = Self;
-}
-
-impl ExtractComponent for MyComponent {
-    type QueryData = ();
-    type QueryFilter = ();
-
-    fn extract_component(
-        item: QueryItem<'_, '_, Self::QueryData>,
-    ) -> Option<Self::Out> {
-        Some(*item)
-    }
-}
+#[derive(Component, ExtractComponent)]
+#[extract_component_sync_target((Self, OtherDerivedComponents))]
+struct MyComponent;
 ```
+
+Both `SyncComponent` and `ExtractComponent` have also gotten an optional marker type that can be used to bypass orphan rules, see the docs for details.
diff --git a/crates/bevy_anti_alias/src/contrast_adaptive_sharpening/mod.rs b/crates/bevy_anti_alias/src/contrast_adaptive_sharpening/mod.rs
@@ -77,12 +77,13 @@ pub struct CasUniform {
 }
 
 impl SyncComponent for ContrastAdaptiveSharpening {
-    type Out = (DenoiseCas, CasUniform);
+    type Target = (DenoiseCas, CasUniform);
 }
 
 impl ExtractComponent for ContrastAdaptiveSharpening {
     type QueryData = &'static Self;
     type QueryFilter = With<Camera>;
+    type Out = (DenoiseCas, CasUniform);
 
     fn extract_component(item: QueryItem<Self::QueryData>) -> Option<Self::Out> {
         if !item.enabled || item.sharpening_strength == 0.0 {
diff --git a/crates/bevy_anti_alias/src/smaa/mod.rs b/crates/bevy_anti_alias/src/smaa/mod.rs
@@ -41,8 +41,6 @@ use bevy_derive::{Deref, DerefMut};
 use bevy_ecs::{
     component::Component,
     entity::Entity,
-    lifecycle::Remove,
-    observer::On,
     query::With,
     reflect::ReflectComponent,
     resource::Resource,
@@ -85,6 +83,13 @@ pub struct SmaaPlugin;
 /// for a [`bevy_camera::Camera`].
 #[derive(Clone, Copy, Default, Component, Reflect, ExtractComponent)]
 #[reflect(Component, Default, Clone)]
+#[extract_component_sync_target((
+	Self,
+	SmaaTextures,
+    SmaaPipelines,
+    SmaaBindGroups,
+    ViewSmaaPipelines,
+))]
 #[doc(alias = "SubpixelMorphologicalAntiAliasing")]
 pub struct Smaa {
     /// A predefined set of SMAA parameters: i.e. a quality level.
@@ -331,17 +336,6 @@ impl Plugin for SmaaPlugin {
             return;
         };
 
-        // TODO: remove this manual cleanup when ExtractComponent gets support
-        // for cleanup of derived components
-        render_app.add_observer(|event: On<Remove, Smaa>, mut commands: Commands| {
-            commands.entity(event.entity).remove::<(
-                SmaaTextures,
-                SmaaPipelines,
-                SmaaBindGroups,
-                ViewSmaaPipelines,
-            )>();
-        });
-
         render_app
             .insert_resource(smaa_luts)
             .init_resource::<SmaaSpecializedRenderPipelines>()
diff --git a/crates/bevy_anti_alias/src/taa/mod.rs b/crates/bevy_anti_alias/src/taa/mod.rs
@@ -130,7 +130,7 @@ impl Default for TemporalAntiAliasing {
 }
 
 impl SyncComponent for TemporalAntiAliasing {
-    type Out = Self;
+    type Target = Self;
 }
 
 fn temporal_anti_alias(
diff --git a/crates/bevy_core_pipeline/src/oit/mod.rs b/crates/bevy_core_pipeline/src/oit/mod.rs
@@ -23,7 +23,7 @@ use resolve::OitResolvePlugin;
 
 use crate::{
     core_3d::main_transparent_pass_3d,
-    oit::resolve::node::oit_resolve,
+    oit::resolve::{node::oit_resolve, OitResolvePipelineId},
     schedule::{Core3d, Core3dSystems},
 };
 
@@ -37,6 +37,7 @@ pub mod resolve;
 // This should probably be done by adding an enum to this component.
 // We use the same struct to pass on the settings to the drawing shader.
 #[derive(Clone, Copy, ExtractComponent, Reflect, ShaderType, Component)]
+#[extract_component_sync_target((Self, OrderIndependentTransparencySettingsOffset, OitResolvePipelineId))]
 #[reflect(Clone, Default)]
 pub struct OrderIndependentTransparencySettings {
     /// Controls how many fragments will be exactly sorted.
diff --git a/crates/bevy_core_pipeline/src/prepass/background_motion_vectors.rs b/crates/bevy_core_pipeline/src/prepass/background_motion_vectors.rs
@@ -56,12 +56,13 @@ use crate::{
 pub struct NoBackgroundMotionVectors;
 
 impl SyncComponent for NoBackgroundMotionVectors {
-    type Out = Self;
+    type Target = Self;
 }
 
 impl ExtractComponent for NoBackgroundMotionVectors {
     type QueryData = Read<NoBackgroundMotionVectors>;
     type QueryFilter = ();
+    type Out = Self;
 
     fn extract_component(_item: QueryItem<'_, '_, Self::QueryData>) -> Option<Self::Out> {
         Some(NoBackgroundMotionVectors)
diff --git a/crates/bevy_pbr/src/atmosphere/mod.rs b/crates/bevy_pbr/src/atmosphere/mod.rs
@@ -373,12 +373,13 @@ impl From<AtmosphereSettings> for GpuAtmosphereSettings {
 }
 
 impl SyncComponent for GpuAtmosphereSettings {
-    type Out = Self;
+    type Target = Self;
 }
 
 impl ExtractComponent for GpuAtmosphereSettings {
     type QueryData = Read<AtmosphereSettings>;
     type QueryFilter = (With<Camera3d>, With<Atmosphere>);
+    type Out = Self;
 
     fn extract_component(item: QueryItem<'_, '_, Self::QueryData>) -> Option<Self::Out> {
         Some(item.clone().into())
diff --git a/crates/bevy_pbr/src/contact_shadows.rs b/crates/bevy_pbr/src/contact_shadows.rs
@@ -81,12 +81,13 @@ impl From<ContactShadows> for ContactShadowsUniform {
 }
 
 impl SyncComponent for ContactShadows {
-    type Out = Self;
+    type Target = Self;
 }
 
 impl ExtractComponent for ContactShadows {
     type QueryData = &'static ContactShadows;
     type QueryFilter = ();
+    type Out = Self;
 
     fn extract_component(settings: QueryItem<'_, '_, Self::QueryData>) -> Option<Self::Out> {
         Some(*settings)
diff --git a/crates/bevy_pbr/src/decal/clustered.rs b/crates/bevy_pbr/src/decal/clustered.rs
@@ -185,7 +185,7 @@ impl Plugin for ClusteredDecalPlugin {
 }
 
 impl SyncComponent<ClusteredDecalPlugin> for ClusteredDecal {
-    type Out = Self;
+    type Target = Self;
 }
 
 // This is needed because of the orphan rule not allowing implementing
diff --git a/crates/bevy_pbr/src/lib.rs b/crates/bevy_pbr/src/lib.rs
@@ -381,17 +381,17 @@ pub fn stbn_placeholder() -> Image {
 }
 
 impl SyncComponent<PbrPlugin> for DirectionalLight {
-    type Out = Self;
+    type Target = Self;
 }
 impl SyncComponent<PbrPlugin> for PointLight {
-    type Out = Self;
+    type Target = Self;
 }
 impl SyncComponent<PbrPlugin> for SpotLight {
-    type Out = Self;
+    type Target = Self;
 }
 impl SyncComponent<PbrPlugin> for AmbientLight {
-    type Out = Self;
+    type Target = Self;
 }
 impl SyncComponent<PbrPlugin> for ShadowFilteringMethod {
-    type Out = Self;
+    type Target = Self;
 }
diff --git a/crates/bevy_pbr/src/light_probe/generate.rs b/crates/bevy_pbr/src/light_probe/generate.rs
@@ -1107,5 +1107,5 @@ pub fn generate_environment_map_light(
 }
 
 impl SyncComponent<EnvironmentMapGenerationPlugin> for GeneratedEnvironmentMapLight {
-    type Out = RenderEnvironmentMap;
+    type Target = RenderEnvironmentMap;
 }
diff --git a/crates/bevy_pbr/src/ssr/mod.rs b/crates/bevy_pbr/src/ssr/mod.rs
@@ -516,12 +516,17 @@ pub fn prepare_ssr_settings(
 }
 
 impl SyncComponent for ScreenSpaceReflections {
-    type Out = ScreenSpaceReflectionsUniform;
+    type Target = (
+        ScreenSpaceReflectionsUniform,
+        ViewScreenSpaceReflectionsUniformOffset,
+        ScreenSpaceReflectionsPipelineId,
+    );
 }
 
 impl ExtractComponent for ScreenSpaceReflections {
     type QueryData = Read<ScreenSpaceReflections>;
     type QueryFilter = ();
+    type Out = ScreenSpaceReflectionsUniform;
 
     fn extract_component(settings: QueryItem<'_, '_, Self::QueryData>) -> Option<Self::Out> {
         if !DEPTH_TEXTURE_SAMPLING_SUPPORTED {
diff --git a/crates/bevy_pbr/src/volumetric_fog/mod.rs b/crates/bevy_pbr/src/volumetric_fog/mod.rs
@@ -108,5 +108,5 @@ impl Plugin for VolumetricFogPlugin {
 }
 
 impl SyncComponent<VolumetricFogPlugin> for FogVolume {
-    type Out = Self;
+    type Target = Self;
 }
diff --git a/crates/bevy_post_process/src/bloom/settings.rs b/crates/bevy_post_process/src/bloom/settings.rs
@@ -221,12 +221,13 @@ pub enum BloomCompositeMode {
 }
 
 impl SyncComponent for Bloom {
-    type Out = (Self, BloomUniforms);
+    type Target = (Self, BloomUniforms);
 }
 
 impl ExtractComponent for Bloom {
     type QueryData = (&'static Self, &'static Camera);
     type QueryFilter = With<Hdr>;
+    type Out = (Self, BloomUniforms);
 
     fn extract_component((bloom, camera): QueryItem<'_, '_, Self::QueryData>) -> Option<Self::Out> {
         match (
diff --git a/crates/bevy_post_process/src/dof/mod.rs b/crates/bevy_post_process/src/dof/mod.rs
@@ -655,7 +655,7 @@ impl SpecializedRenderPipeline for DepthOfFieldPipeline {
 }
 
 impl SyncComponent for DepthOfField {
-    type Out = (
+    type Target = (
         DepthOfField,
         DepthOfFieldUniform,
         DepthOfFieldPipelines,
@@ -683,7 +683,7 @@ fn extract_depth_of_field_settings(
 
         // Depth of field is nonsensical without a perspective projection.
         let Projection::Perspective(ref perspective_projection) = *projection else {
-            entity_commands.remove::<<DepthOfField as SyncComponent>::Out>();
+            entity_commands.remove::<<DepthOfField as SyncComponent>::Target>();
 
             continue;
         };
diff --git a/crates/bevy_post_process/src/effect_stack/chromatic_aberration.rs b/crates/bevy_post_process/src/effect_stack/chromatic_aberration.rs
@@ -86,12 +86,13 @@ impl Default for ChromaticAberration {
 }
 
 impl SyncComponent for ChromaticAberration {
-    type Out = Self;
+    type Target = Self;
 }
 
 impl ExtractComponent for ChromaticAberration {
     type QueryData = Read<ChromaticAberration>;
     type QueryFilter = With<Camera>;
+    type Out = Self;
 
     fn extract_component(
         chromatic_aberration: QueryItem<'_, '_, Self::QueryData>,
diff --git a/crates/bevy_post_process/src/effect_stack/vignette.rs b/crates/bevy_post_process/src/effect_stack/vignette.rs
@@ -103,12 +103,13 @@ impl Default for Vignette {
 }
 
 impl SyncComponent for Vignette {
-    type Out = Self;
+    type Target = Self;
 }
 
 impl ExtractComponent for Vignette {
     type QueryData = Read<Vignette>;
     type QueryFilter = With<Camera>;
+    type Out = Self;
 
     fn extract_component(vignette: QueryItem<'_, '_, Self::QueryData>) -> Option<Self::Out> {
         // Skip the postprocessing phase entirely if the intensity is zero.
diff --git a/crates/bevy_post_process/src/motion_blur/mod.rs b/crates/bevy_post_process/src/motion_blur/mod.rs
@@ -116,12 +116,13 @@ impl Default for MotionBlur {
 }
 
 impl SyncComponent for MotionBlur {
-    type Out = MotionBlurUniform;
+    type Target = MotionBlurUniform;
 }
 
 impl ExtractComponent for MotionBlur {
     type QueryData = &'static Self;
     type QueryFilter = With<Camera>;
+    type Out = MotionBlurUniform;
 
     fn extract_component(item: QueryItem<Self::QueryData>) -> Option<Self::Out> {
         Some(MotionBlurUniform {
diff --git a/crates/bevy_render/macros/src/extract_component.rs b/crates/bevy_render/macros/src/extract_component.rs
@@ -38,15 +38,34 @@ pub fn derive_extract_component(input: TokenStream) -> TokenStream {
         }
     };
 
+    let sync_target = if let Some(attr) = ast
+        .attrs
+        .iter()
+        .find(|a| a.path().is_ident("extract_component_sync_target"))
+    {
+        let sync_target = match attr.parse_args::<syn::Type>() {
+            Ok(sync_target) => sync_target,
+            Err(e) => return e.to_compile_error().into(),
+        };
+
+        quote! {
+            #sync_target
+        }
+    } else {
+        quote! {
+            Self
+        }
+    };
+
     TokenStream::from(quote! {
         impl #impl_generics #bevy_render_path::sync_component::SyncComponent for #struct_name #type_generics #where_clause {
-            type Out = Self;
+            type Target = #sync_target;
         }
 
         impl #impl_generics #bevy_render_path::extract_component::ExtractComponent for #struct_name #type_generics #where_clause {
             type QueryData = &'static Self;
-
             type QueryFilter = #filter;
+            type Out = Self;
 
             fn extract_component(item: #bevy_ecs_path::query::QueryItem<'_, '_, Self::QueryData>) -> Option<Self::Out> {
                 Some(item.clone())
diff --git a/crates/bevy_render/macros/src/lib.rs b/crates/bevy_render/macros/src/lib.rs
@@ -32,6 +32,7 @@ pub fn derive_extract_resource(input: TokenStream) -> TokenStream {
 /// See `ExtractComponentPlugin` to actually perform the extraction.
 ///
 /// If you only want to extract a component conditionally, you may use the `extract_component_filter` attribute.
+/// To specify `SyncComponent::Target`, you can use the `extract_component_sync_target` attribute.
 ///
 /// # Example
 ///
@@ -41,6 +42,7 @@ pub fn derive_extract_resource(input: TokenStream) -> TokenStream {
 ///
 /// #[derive(Component, Clone, ExtractComponent)]
 /// #[extract_component_filter(With<Camera>)]
+/// #[extract_component_sync_target((Self, OtherNeedsCleanup))]
 /// pub struct Foo {
 ///     pub should_foo: bool,
 /// }
@@ -51,7 +53,10 @@ pub fn derive_extract_resource(input: TokenStream) -> TokenStream {
 ///     pub should_bar: bool,
 /// }
 /// ```
-#[proc_macro_derive(ExtractComponent, attributes(extract_component_filter))]
+#[proc_macro_derive(
+    ExtractComponent,
+    attributes(extract_component_filter, extract_component_sync_target)
+)]
 pub fn derive_extract_component(input: TokenStream) -> TokenStream {
     extract_component::derive_extract_component(input)
 }
diff --git a/crates/bevy_render/src/camera.rs b/crates/bevy_render/src/camera.rs
diff --git a/crates/bevy_render/src/extract_component.rs b/crates/bevy_render/src/extract_component.rs
diff --git a/crates/bevy_render/src/extract_plugin.rs b/crates/bevy_render/src/extract_plugin.rs
diff --git a/crates/bevy_render/src/sync_component.rs b/crates/bevy_render/src/sync_component.rs
diff --git a/examples/2d/mesh2d_manual.rs b/examples/2d/mesh2d_manual.rs
diff --git a/examples/shader_advanced/custom_shader_instancing.rs b/examples/shader_advanced/custom_shader_instancing.rs

Original file line number	Diff line number	Diff line change
`@@ -77,12 +77,13 @@ pub struct CasUniform {`
`77`	`77`	`}`
`78`	`78`
`79`	`79`	`impl SyncComponent for ContrastAdaptiveSharpening {`
`80`		`- type Out = (DenoiseCas, CasUniform);`
	`80`	`+ type Target = (DenoiseCas, CasUniform);`
`81`	`81`	`}`
`82`	`82`
`83`	`83`	`impl ExtractComponent for ContrastAdaptiveSharpening {`
`84`	`84`	`type QueryData = &'static Self;`
`85`	`85`	`type QueryFilter = With<Camera>;`
	`86`	`+ type Out = (DenoiseCas, CasUniform);`
`86`	`87`
`87`	`88`	`fn extract_component(item: QueryItem<Self::QueryData>) -> Option<Self::Out> {`
`88`	`89`	`if !item.enabled \|\| item.sharpening_strength == 0.0 {`
Original file line number	Diff line number	Diff line change
`@@ -130,7 +130,7 @@ impl Default for TemporalAntiAliasing {`
`130`	`130`	`}`
`131`	`131`
`132`	`132`	`impl SyncComponent for TemporalAntiAliasing {`
`133`		`- type Out = Self;`
	`133`	`+ type Target = Self;`
`134`	`134`	`}`
`135`	`135`
`136`	`136`	`fn temporal_anti_alias(`
Original file line number	Diff line number	Diff line change
`@@ -373,12 +373,13 @@ impl From<AtmosphereSettings> for GpuAtmosphereSettings {`
`373`	`373`	`}`
`374`	`374`
`375`	`375`	`impl SyncComponent for GpuAtmosphereSettings {`
`376`		`- type Out = Self;`
	`376`	`+ type Target = Self;`
`377`	`377`	`}`
`378`	`378`
`379`	`379`	`impl ExtractComponent for GpuAtmosphereSettings {`
`380`	`380`	`type QueryData = Read<AtmosphereSettings>;`
`381`	`381`	`type QueryFilter = (With<Camera3d>, With<Atmosphere>);`
	`382`	`+ type Out = Self;`
`382`	`383`
`383`	`384`	`fn extract_component(item: QueryItem<'_, '_, Self::QueryData>) -> Option<Self::Out> {`
`384`	`385`	`Some(item.clone().into())`
Original file line number	Diff line number	Diff line change
`@@ -81,12 +81,13 @@ impl From<ContactShadows> for ContactShadowsUniform {`
`81`	`81`	`}`
`82`	`82`
`83`	`83`	`impl SyncComponent for ContactShadows {`
`84`		`- type Out = Self;`
	`84`	`+ type Target = Self;`
`85`	`85`	`}`
`86`	`86`
`87`	`87`	`impl ExtractComponent for ContactShadows {`
`88`	`88`	`type QueryData = &'static ContactShadows;`
`89`	`89`	`type QueryFilter = ();`
	`90`	`+ type Out = Self;`
`90`	`91`
`91`	`92`	`fn extract_component(settings: QueryItem<'_, '_, Self::QueryData>) -> Option<Self::Out> {`
`92`	`93`	`Some(*settings)`
Original file line number	Diff line number	Diff line change
`@@ -185,7 +185,7 @@ impl Plugin for ClusteredDecalPlugin {`
`185`	`185`	`}`
`186`	`186`
`187`	`187`	`impl SyncComponent<ClusteredDecalPlugin> for ClusteredDecal {`
`188`		`- type Out = Self;`
	`188`	`+ type Target = Self;`
`189`	`189`	`}`
`190`	`190`
`191`	`191`	`// This is needed because of the orphan rule not allowing implementing`
Original file line number	Diff line number	Diff line change
`@@ -381,17 +381,17 @@ pub fn stbn_placeholder() -> Image {`
`381`	`381`	`}`
`382`	`382`
`383`	`383`	`impl SyncComponent<PbrPlugin> for DirectionalLight {`
`384`		`- type Out = Self;`
	`384`	`+ type Target = Self;`
`385`	`385`	`}`
`386`	`386`	`impl SyncComponent<PbrPlugin> for PointLight {`
`387`		`- type Out = Self;`
	`387`	`+ type Target = Self;`
`388`	`388`	`}`
`389`	`389`	`impl SyncComponent<PbrPlugin> for SpotLight {`
`390`		`- type Out = Self;`
	`390`	`+ type Target = Self;`
`391`	`391`	`}`
`392`	`392`	`impl SyncComponent<PbrPlugin> for AmbientLight {`
`393`		`- type Out = Self;`
	`393`	`+ type Target = Self;`
`394`	`394`	`}`
`395`	`395`	`impl SyncComponent<PbrPlugin> for ShadowFilteringMethod {`
`396`		`- type Out = Self;`
	`396`	`+ type Target = Self;`
`397`	`397`	`}`